Most of the Haudenosaunee tribes sided with the British.
Because the British were like, "If you guys help us kill George Washington and his anarchy group, we promise to let you have all the land you want /s" Of course that promise would only be words lost to the wind.
But a decade earlier, George Washington saw the British wipe out the Indian and French Army because they wanted control over American and Indian territory.
Now the British wanted the American settlers to pay for the war and enslave the Americna settlers and eventually the Native Americans. George Washington was like fuck this shit, anyone who wants to control us will die.
So they British, and the Haudenosaunee died.